1. Field of the Invention
The present invention relates to surgical devices and associated methods and, more particularly, to a tissue retraction device configured to determine, measure, and/or control the rate and/or magnitude of the force and/or strain applied or imparted to the tissue being retracted, and associated apparatus and method.
2. Description of Related Art
Some surgeries require opening a portion of the body so as to provide sufficient exposure of the subject of the procedure and to provide access for the physician to operate on the subject. For example, cardio-thoracic surgery requires opening the thoracic skeletal cavity in order to access the organs therein. Such access to the thoracic skeletal cavity may be gained through, for example, the sternum along the anterior midline, in a procedure known as a median sternotomy, or laterally between ribs, in a procedure known as a lateral thoracotomy. Once the appropriate incision(s) have been made into the cavity, the incision must be enlarged in order to allow access into the thoracic skeletal cavity. Such enlargement of the incision is often accomplished by a retraction device for separating the tissue surrounding the incision.
In some instances, however, the retraction device may exert significant forces on the tissue surrounding the incision, wherein such forces may sometimes adversely affect the tissue or any surrounding skeletal components. For example, during a median sternotomy, if the incised sternum is retracted too quickly, the sternum may completely fracture. As a result, the patient may require post-operative stabilization of the area, may experience a high level of post-operative pain, and may require an extended healing time. Some previous attempts at limiting such risks of partial stenotomies have included J-shape cuts at the mid-line of the sternum. However, such measures may also result in post operative instability of the sternal bone. In any instance, retraction may cause damage to the tissue surrounding the incision that can result in acute and chronic post operative pain to the patient, as well as other co-morbidities such as, for example, sternal dehesion, mediastenitis, lung atelectasis, pneumonia, or death. As one example, some studies report post-cardiac surgery pain (PCP) in about 80% of patients at three months post-operatively, and in about 28%-61% of patients at one to three years post-operatively.
Thus, there exists a need for a method and apparatus capable of determining a more optimal manner for accomplishing retraction of an incision, in procedures where such retraction is necessary for gaining access to a body cavity, in order to minimize trauma to the tissue surrounding the incision so as to, in turn, minimize post-operative stabilization requirements and post-operative pain, as well as to decrease the required healing time following such a procedure. Such a method and apparatus should also be applicable to determining and/or implementing a retraction procedure that provides the necessary access to body cavity while minimizing the discussed limitations or risks of a retraction procedure when such a situation is encountered.